Alice Stewart (1906-2002)

Stewart studied medicine at Cambridge University. During the Second World War she investigated health risks of factory workers, and her research saw her elected as the youngest ever Fellow of the Royal College of Physicians.

Between 1953 and 1955, Stewart launched a landmark study to investigate causes of childhood cancer. She analysed questionnaires completed by women whose children had died from cancer. Her results showed X‑rays during pregnancy doubled the risk of childhood cancer.

Stewart’s findings were not welcomed in the medical community. She said X‑rays ‘were the favourite toy of the medical profession’, but medical authorities were unwilling to recognise that radiation was as dangerous as Stewart claimed. Ian Donald’s invention of the ultrasound machine in the 1970s provided an alternative. Overwhelming evidence convinced major medical bodies to stop X‑raying pregnant women.

Stewart later became an antinuclear and radiation activist. She co-published a study with Thomas Mancuso that showed workers at nuclear weapons plants had a greater cancer risk than previously thought. Their statistical methods were criticised by Oxford epidemiologist Richard Doll, but their findings attracted public attention and prompted government investigations in the late 1970s.